Malaria is a life-threatening disease caused by parasites of the Plasmodium species, which is transmitted to humans through the bites of infected female Anopheles mosquitoes. It is a prevalent infectious disease that particularly affects tropical and subtropical regions worldwide. Malaria has a significant impact on global health, posing a risk to millions of individuals and leading to hundreds of thousands of deaths annually.
Historically, malaria has been a major public health concern. The disease was first identified in ancient China around 2700 BC, and descriptions of malaria-like symptoms can be found in ancient Egyptian writings and Indian Ayurvedic texts. In the 17th century, European colonizers encountered malaria in tropical regions, including areas now known as the Americas and Africa. The term "malaria" originated from the Italian words "mala aria," which means "bad air," as it was believed that the disease was caused by foul-smelling air in swampy areas. It was not until the late 19th century that Sir Ronald Ross, an English physician, discovered that the true cause of malaria was the mosquito as the vector transmitting the disease.
Malaria is present in approximately 90 countries, with sub-Saharan Africa, South Asia, and parts of Central and South America experiencing the highest burden of the disease. According to the World Health Organization (WHO), there were an estimated 228 million cases of malaria worldwide and over 400,000 deaths in 2018. However, it is important to acknowledge that these figures may underestimate the actual burden due to under-reporting and limited access to healthcare in many affected regions.
The primary mode of malaria transmission is through the bite of infected female Anopheles mosquitoes. There are five species of Plasmodium that can cause malaria in humans, with P. falciparum being the most lethal and responsible for the majority of malaria-related deaths. In addition to mosquito bites, malaria can also be transmitted through blood transfusion, sharing of contaminated needles, or from mother to child during pregnancy and childbirth.
Malaria affects individuals of all age groups, but young children and pregnant women are particularly vulnerable. In areas with high malaria transmission, children under the age of five are at the greatest risk of severe illness and death. Pregnant women are also more susceptible to malaria, and the infection can result in adverse outcomes such as maternal anemia, low birth weight, and an increased risk of infant mortality.
Key statistics pertaining to malaria include the following: - In 2018, approximately 94% of malaria cases and deaths occurred in the WHO African Region. - Two-thirds of malaria deaths worldwide were children under five years old. - In regions with high transmission, such as sub-Saharan Africa, the disease is a leading cause of morbidity and mortality.
Multiple factors contribute to the transmission and spread of malaria, including mosquito breeding sites like stagnant water bodies such as puddles, swamps, and irrigated fields. Inadequate use of insecticide-treated bed nets, indoor residual spraying, and larval control measures also contribute to increased mosquito populations and higher transmission rates. Additionally, climate and geography play a role, as malaria transmission is influenced by factors such as rainfall patterns, temperature, and altitude. Socioeconomic conditions, limited access to healthcare, and inadequate diagnostic and treatment facilities further contribute to the persistence of malaria in endemic regions.
Malaria disproportionately impacts certain regions and populations, with sub-Saharan Africa bearing the highest burden with about 93% of malaria cases and deaths worldwide. Within this region, children under five, pregnant women, and individuals living with HIV/AIDS are particularly vulnerable. In Asia, countries like India, Indonesia, and Myanmar have a high malaria burden. Central and South America, including the Amazon Basin region, are also affected by the disease. However, the prevalence and severity of malaria can vary across countries and even within regions due to differences in malaria control measures, local mosquito species and their ability to transmit malaria, availability of diagnostic tools and effective treatment, and access to healthcare services.
In conclusion, malaria remains a significant global public health issue, especially in tropical and subtropical regions. Its high prevalence, transmission through infected mosquitoes, and impact on vulnerable populations make it a major cause of illness and death. Efforts to combat malaria include vector control measures, early diagnosis, prompt treatment, and research into new interventions such as vaccines.

Download Data(下载数据)

Seasonal Patterns:
According to the data, mainland China exhibits a clear seasonal pattern in the number of malaria cases before July 2023. Generally, the number of cases begins to increase in the early months of the year, reaches its peak in the middle of the year, and subsequently declines towards the end of the year. This consistent pattern across multiple years indicates a seasonal transmission pattern for malaria in mainland China.
Peak and Trough Periods:
Typically, the peak period for malaria cases in mainland China occurs in the middle of the year, specifically during the months of June and July. This timeframe records the highest number of cases. Conversely, the trough period, which corresponds to the period with the lowest number of cases, usually falls towards the end of the year, specifically in November and December.
Overall Trends:
In general, there is a decreasing trend in the number of malaria cases in mainland China before July 2023. This trend can be observed by comparing the number of cases from year to year. Although there are fluctuations in the monthly counts, the general trend points towards a decline in malaria cases over time.
Discussion:
The seasonal pattern of malaria cases in mainland China suggests the presence of environmental factors that contribute to the transmission and spread of the disease. Malaria is known to be transmitted by mosquitoes, and the peak periods in June and July align with the warmer months when mosquito populations typically thrive. The decrease in cases towards the end of the year may be influenced by factors such as colder temperatures and reduced mosquito activity.
The overall decreasing trend in malaria cases is likely a result of various factors, including improved public health measures, enhanced access to healthcare, and successful malaria control interventions. These efforts may involve the implementation of insecticide-treated bed nets, indoor residual spraying, and prompt diagnosis and treatment of malaria cases.
To maintain the downward trend in malaria cases, it is crucial to continue both monitoring and implementing effective malaria control strategies in mainland China. Additionally, ongoing surveillance and research are necessary to comprehend any emerging trends or changes in the transmission dynamics of malaria, in order to adapt control measures accordingly.